# A discrete mathematics problem by Pankaj Kumar Yadav

**Discrete Mathematics**Level 4

There are 11 sealed bags.It is known that for each i between 0 to 10 (both included) there is a bag that has i red balls and 10-i black balls.One bag is selected at random from these bags, and the first ball drawn is red.The probability that the next drawn ball is also red is of the form a/b, where a and b are coprime.Then a+b is?